Michael Kelley 4366679805 Drivers: hv: vmbus: Prevent load re-ordering when reading ring buffer ... [ Upstream commit b6cae15b57 ] When reading a packet from a host-to-guest ring buffer, there is no memory barrier between reading the write index (to see if there is a packet to read) and reading the contents of the packet. The Hyper-V host uses store-release when updating the write index to ensure that writes of the packet data are completed first. On the guest side, the processor can reorder and read the packet data before the write index, and sometimes get stale packet data. Getting such stale packet data has been observed in a reproducible case in a VM on ARM64. Fix this by using virt_load_acquire() to read the write index, ensuring that reads of the packet data cannot be reordered before it. Preventing such reordering is logically correct, and with this change, getting stale data can no longer be reproduced. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/1648394710-33480-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2022-04-20 09:23:20 +02:00
..
channel.c	Drivers: hv: vmbus: Use after free in __vmbus_open()	2021-05-14 09:50:20 +02:00
channel_mgmt.c	Drivers: hv: vmbus: Replace smp_store_mb() with virt_store_mb()	2022-04-13 21:01:11 +02:00
connection.c	drivers: hv: Fix missing error code in vmbus_connect()	2021-07-14 16:55:59 +02:00
hv.c	hyperv-fixes for 5.10-rc5	2020-11-16 15:02:33 -08:00
hv_balloon.c	hv_balloon: rate-limit "Unhandled message" warning	2022-04-08 14:40:19 +02:00
hv_debugfs.c	hv_debugfs: Make hv_debug_root static	2020-04-04 17:47:43 +01:00
hv_fcopy.c	hv_utils: Always execute the fcopy and vss callbacks in a tasklet	2020-04-23 13:17:11 +00:00
hv_kvp.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
hv_snapshot.c	hv_utils: Always execute the fcopy and vss callbacks in a tasklet	2020-04-23 13:17:11 +00:00
hv_trace.c
hv_trace.h	hyperv-next for 5.8	2020-06-03 15:00:05 -07:00
hv_trace_balloon.h
hv_util.c	hv_utils: Fix passing zero to 'PTR_ERR' warning	2021-07-14 16:55:57 +02:00
hv_utils_transport.c
hv_utils_transport.h
hyperv_vmbus.h	hyperv/vmbus: include linux/bitops.h	2021-11-18 14:03:42 +01:00
Kconfig	Revert "hv: utils: add PTP_1588_CLOCK to Kconfig to fix build"	2022-04-13 21:01:03 +02:00
Makefile
ring_buffer.c	Drivers: hv: vmbus: Prevent load re-ordering when reading ring buffer	2022-04-20 09:23:20 +02:00
vmbus_drv.c	Drivers: hv: vmbus: Fix potential crash on module unload	2022-04-13 21:01:04 +02:00